Was it something McCain said?No, despite jokes to the contrary. "It wasn't Sen. McCain's questions," Petraeus said. "I just got dehydrated." It would be "understandable that there might be some strain on him, though," says David Graham in Newsweek. "Senators were grilling him about President Obama's plan to start withdrawing troops from Afghanistan starting in July 2011," which some call "too aggressive." Slate's Fred Kaplan sees the fainting spell as a "grim metaphor" for how the war's going.

Does this happen often?Sen. Carl Levin (D-MI), who chairs the Senate Armed Services Committee, says he's never seen any witness collapse during a hearing. There is a long, storied history of public figures fainting, however: The first President Bush dramatically slumped over into the lap of the Japanese Prime Minister during a state dinner in 1992, while his son, less impressively, once fainted in 2002 while eating a pretzel and watching a football game.

So why did Petraeus' fainting get so much attention?Along with being the chief strategist for the wars in Iraq and Afghanistan, Petraeus is the most popular military leader of his generation. He's also rumored to have presidential ambitions, despite his frequent denials, and "health issues are always important" for political candidates, says Rutgers political science professor Ross Baker. "People, particularly those who come out of a non-political background, are somewhat of a mystery, and people want to know more about them."